Determine whether or not each of the following statements is true. If a statement is true, prove it. If a statement is false, provide a counterexample and explain how it constitutes a counter-example.
A capacitor consists of two flat, metal plates with unequal areas. Each of the plates starts neutral, and then each plate is connected to a dierent terminal of a battery. After some time, the plates will have excess charge on them, and the magnitude of the excess charge on one plate will equal the magnitude of the excess charge on the other plate.
A. True
B. False
If a wire carries current, then it has a net non-zero charge in it.
A. True
B. False

Answer:

acceleration is the rate of change of the velocity of an object with respect to time. Accelerations are vector quantities. The orientation of an object's acceleration is given by the orientation of the net force acting on that object.

Explanation:

Calculating acceleration involves dividing velocity by time — or in terms of SI units, dividing the meter per second [m/s] by the second [s]. Dividing distance by time twice is the same as dividing distance by the square of time. Thus the SI unit of acceleration is the meter per second squared .

Answer:

Pink - Pluto

Green - Mercury

Red - Mars

Black - Saturn

Blue - Neptune

Yellow - Jupiter

Orange - Jupiter

Milk Color - Venus

Explanation:

The galaxy is full of colors. There are various planets in the galaxy which are different colored. Their color is usually determined by the gases present there. The pink gases present near the Pluto makes Pluto appears to be of magenta or pink colored. The mercury is green colored because it reflects green rays. Mars is called the Red planet because of presence of Martin Rocks there.

Explanation:

momentum = mass x velocity

momentum = 40 x 20 = 800kgm/s

Answer:

800kgm/s

Explanation:

momentum= mass×velocity

= 40×20

= 800kgm/s

Answer:

True.

Explanation:

Total internal reflection is bound to occur when light travels from dense medium to less dense.

From the table given in the question above, we obtained:

Refractive Index of Crown glass = 1.52

Refractive Index of Asphalt = 1.635

From the above, Crown glass has a lower refractive index when compared to Asphalt. This means that Crown glass is less dense than Asphalt.

Therefore, total internal reflection will not occur when light travels from Crown glass to Asphalt because Crown glass is less dense than Asphalt.

Answer:

On heating gases expands than solid and liquid because the molecules gets seperated and the volume increases that causes to expand.

Explanation:

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Answer:

[tex]118\; \rm Hz[/tex].

Explanation:

The frequency [tex]f[/tex] of a wave is equal to the number of wave cycles that go through a point on its path in unit time (where "unit time" is typically equal to one second.)

The wave in this question travels at a speed of [tex]v= 295\; \rm m\cdot s^{-1}[/tex]. In other words, the wave would have traveled [tex]295\; \rm m[/tex] in each second. Consider a point on the path of this wave. If a peak was initially at that point, in one second that peak would be

How many wave cycles can fit into that [tex]295\; \rm m[/tex]? The wavelength of this wave[tex]\lambda = 2.50\; \rm m[/tex] gives the length of one wave cycle. Therefore:

[tex]\displaystyle \frac{295\;\rm m}{2.50\; \rm m} = 118[/tex].

That is: there are [tex]118[/tex] wave cycles in [tex]295\; \rm m[/tex] of this wave.

On the other hand, Because that [tex]295\; \rm m[/tex] of this wave goes through that point in each second, that [tex]118[/tex] wave cycles will go through that point in the same amount of time. Hence, the frequency of this wave would be

Because one wave cycle per second is equivalent to one Hertz, the frequency of this wave can be written as:

[tex]f = 118\; \rm s^{-1} = 118\; \rm Hz[/tex].

The calculations above can be expressed with the formula:

[tex]\displaystyle f = \frac{v}{\lambda}[/tex],

where

Answer:

118

Explanation:

Answer:

Explanation:

T = 8 s

angular frequency ω = 2π / T

= 2 π / 8

= π / 4

x ( t ) = A ( sinωt + π / 2 ) because initial phase difference is π / 2

= A cos ωt

= A cos π t / 4  

v = Aω sinωt

= 2 x π / 4 sinωt

= .5 π sinπt / 4

when t = 2

v = .5 π sinπ x 2 / 4

= .5 π x 1

= 1.57  cm /s

At t = 3 s

v = .5 π sin π x 3 / 4

= .5 π sin 135°

= .5 π / √ 2

= 1.11 cm /s

Answer:

Explanation:

To add or subtract two vectors, add or subtract the corresponding components. Let →u=⟨u1,u2⟩ and →v=⟨v1,v2⟩ be two vectors. The sum of two or more vectors is called the resultant. The resultant of two vectors can be found using either the parallelogram method or the triangle method .

Answer:

v = 46.67 km/h

Explanation:

We will use the following formula throughout this numerical:

s = vt

where,

s = distance covered

v = speed

t =  time taken

FOR FIRST 30 km:

s = 30 km

v = 30 km/h

t = t₃₀ = ?

Therefore,

30 km = (30 km/h)(t₃₀)

t₃₀ = (30 km)/(30 km/h)

t₃₀ = 1 h

FOR TOTAL 100 km:

s = 100 km

v = 40 km/h (Average Speed)

t = total time = ?

Therefore,

100 km = (40 km/h)(t)

t = (100 km)/(40 km/h)

t = 2.5 h

FOR LAST 70 km:

s = 70 km

t₇₀ = t - t₃₀ = 2.5 h - 1 h = 1.5 h

v = v₇₀ = ?

Therefore,

70 km = v(1.5 h)

v = 70 km/1.5 h

v = 46.67 km/h

Answer:

Explanation:

Solution,

When a certain object comes in motion from rest, in the case, initial velocity = 0 m/s

Initial velocity ( u ) = 0 m/s

Final velocity ( v ) = 72 km/h ( Given)

We have to convert 72 km /h in m/s

[tex]72 \: km \: per \: hour[/tex]

[tex] = 72 \times \frac{1000}{60 \times 60} [/tex]

[tex] = 20 [/tex] m/s

Final velocity ( v ) = 20 m/s

Time taken ( t ) = 2 seconds

Acceleration (a) = ?

Now,

we have,

[tex]a = \frac{v - u}{t} [/tex]

[tex]a = \frac{20 - 0}{2} [/tex]

[tex]a = \frac{20}{2} [/tex]

[tex]a = 10 [/tex] m/s ^2

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Explanation:

(b) We know that,

1 day = 24 hours

1 hour = 3600 s

So, we found that, 1 day = 86400 s

We need to find the 360 days into seconds. So,

1 day = 86400 s

360 days = 86400×360

360 days = 31104000 seconds

(d) Weight of a body, W = 600 N

Acceleration due to gravity on mars is 3.7 m/s²

Weight, W = mg

m is mass of body

[tex]m=\dfrac{W}{g}\\\\m=\dfrac{600}{3.7}\\\\m=162.16\ kg[/tex]

(e) Mass of body, m = 100 kg

Acceleration due to gravity on the moon, 1.6 m/s²

Weight, W = 100 × 1.6

W = 160 N

Answer:

Increase

Explanation:

Resonance is a phenomenon which occurs when a body A in motion set another body B into motion of it own natural frequency. So for resonance to be minimize in a body is to increase the width to span ratio. So as to reduce the overall vibration which affects directly building resonance, the stiffness or trusses and girders should be increase. The increase in this aspect helps to reinforce building structure and support.

Answer:

1) a    α,  m   I,  W=F.d    W =τ . θ,

2)  a = v²/r

Explanation:

1) The amounts of rotational and translational motion are related

acceleration is

        a = d²x / dt²

    linear displacement is equivalent to angular rotation, therefore angular acceleration is

      α = d²θ / dt²

force in linear motion is equivalent to moment in endowment motion

       F = m a

       τ = I α

the mass is the inertia of the translation, in rotational motion the moment of inertia is the rotational inertia

          I = m r²

Work is defined by W = F. d

in rotation it is defined by W = τ . θ

The linear momentum is p = mv

the angular momentum L = I w

momentum the linear motion is I = F dt

in the rotation it is I = τ dt

2) The velocity is a vector therefore it has modulus and direction, linear acceleration changes the modulus of velocity, whereas circular motion changes the direction (the other element of the vector).

      [tex]a_{c}[/tex]Ac = v²/r

Answer:

88 %

Explanation:

The rate of heat loss by a conducting material of thermal conductivity K, cross-sectional area,A and thickness d with a temperature gradient ΔT is given by

P = KAΔT/d

The total heat lost by the styrofoam wall is P₁ = K₁A₁ΔT₁/d₁ where K₁ =thermal conductivity of styrofoam wall 0.033 W/m-K, A₁ = area of styrofoam wall = 17 m², ΔT₁ = temperature gradient between inside and outside of the wall and d₁ = thickness of styrofoam wall = 0.20 m

The total heat lost by the glass window is P₂ = K₂A₂ΔT₂/d₂ where K₂ =thermal conductivity of glass window pane wall 0.96 W/m-K, A₂ = area of glass window pane = 0.15 m², ΔT₂ = temperature gradient between inside and outside of the window and d₂ = thickness of glass window pane = 7 mm = 0.007 m

The total heat lost is P = P₁ + P₂ = K₁A₁ΔT₁/d₁ + K₂A₂ΔT₂/d₂

Now, since the temperatures of both inside and outside of both window and wall are the same, ΔT₁ = ΔT₂ = ΔT

So, P = K₁A₁ΔT/d₁ + K₂A₂ΔT/d₂

Since P₂ = K₂A₂ΔT₂/d₂ = K₂A₂ΔT/d₂is the heat lost by the window, the fraction of the heat lost by the window from the total heat lost is

P₂/P = K₂A₂ΔT/d₂ ÷ (K₁A₁ΔT/d₁ + K₂A₂ΔT/d₂)

= 1/(K₁A₁ΔT/d₁÷K₂A₂ΔT/d₂ + 1)

= 1/(K₁A₁d₂÷K₂A₂d₁ + 1)

= 1/[(0.033 W/m-K × 17 m² × 0.007 m ÷ 0.96 W/m-K × 0.15 m² × 0.20 m) + 1]

= 1/(0.003927/0.0288 + 1)

= 1/(0.1364 + 1)

= 1/1.1364

= 0.88.

The percentage is thus P₂/P × 100 % = 0.88 × 100 % = 88 %

The percentage of heat lost by window of the total heat is 88 %

Answer:

a. 2 Hz b. 0.5 cycles c . 0 V

Explanation:

a. What is period of armature?

Since it takes the armature 30 seconds to complete 60 cycles, and frequency f = number of cycles/ time = 60 cycles/ 30 s = 2 cycles/ s = 2 Hz

b. How many cycles are completed in T/2 sec?

The period, T = 1/f = 1/2 Hz = 0.5 s.

So, it takes 0.5 s to complete 1 cycles. At t = T/2 = 0.5/2 = 0.25 s,

Since it takes 0.5 s to complete 1 cycle, then the number of cycles it completes in 0.25 s is 0.25/0.5 = 0.5 cycles.

c. What is the maximum emf produced when the armature completes 180° rotation?

Since the emf E = E₀sinθ and when θ = 180°, sinθ = sin180° = 0

E = E₀ × 0 = 0

E = 0

So, at 180° rotation, the maximum emf produced is 0 V.

Answer:

Explanation:

We shall apply law of conservation of momentum to know velocity after collision . Let it be v .

total momentum before collision = total momentum after collision

15 x 1.5 - 12 x .75 = ( 15 + 12 ) v

v = .5 m /s

kinetic energy before collision

1/2 x 15 x 1.5² + 1/2 x 12 x .75²

= 16.875 + 3.375

= 20.25 J

kinetic energy after collision

= 1/2 x ( 15 + 12 ) x .5²

= 3.375 J

Loss of energy = 16.875 J

This energy appear as heat and sound energy that is produced during collision .

Answer:

car is moving away its direction is negative.

the speed must also be negative.

speed this distance decreases the acceleration is negative and if the speed is increasing the acceleration is positive.

Explanation:

In the exercise they indicate that the direction to the motion sensor is positive, as they indicate that the car is moving away its direction is negative.

The speed of the car is

           v = (x₂-x₁) / t

As the positions are negative, and the car moves away the speed must also be negative.

The analysis for acceleration must be very careful if the speed this distance decreases the acceleration is negative and if the speed is increasing the acceleration is positive.

Answer: b) - 8.0 [tex]m/s^{2}[/tex]

Explanation: Acceleration is a vector indicating a rate an object's velocity changes over time:

a = [tex]\frac{v}{t}[/tex]

and its SI unit is [tex]m/s^{2}[/tex]

For the minivan to stop, it takes a period of 0.5s:

a = [tex]\frac{4.0}{0.5}[/tex]

a = 8.0 [tex]m/s^{2}[/tex]

As a vector, acceleration has magnitude (8[tex]m/s^{2}[/tex]) and direction. Since it is stopping, the minivan has a direction opposite to the other car, which means acceleration is negative. So: a = [tex]- 8.0 m/s^{2}[/tex].

Answer:

b. Red light is transmitted through and reflected by the glass

Explanation:

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All of the wavelengths of the red light are absorbed when it passes through a translucent red glass window, but the red light is transmitted and reflected.

Therefore, the correct answer is option b) Red light is transmitted through and reflected by the glass.

To learn more about light refer to:

https://brainly.com/question/12002703

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Answer:

B. A negative particle outside the nucleus

Explanation:

Electrons are very small particles orbiting outside of the nucleus of an atom. They carry negative charges.

The nucleus only contains protons and neutrons. Protons are positive, and neutrons have no charge (i.e. neutral)

Answer: The only advantage cutting crops with a sickle is that its very effective for cutting lodged crops.

Answer:

1. Fleming's left hand rule

2. It must be projected towards the east

Explanation:

Fleming's left-hand rule states that; When a current-carrying conductor is placed in an external magnetic field, the conductor experiences a force perpendicular to both the field and to the direction of the current flow. This rule was first put forward by John Ambrose Fleming in the later part of the nineteenth century.

Hence if the thumb, fore finger and middle finger of the lefthand are held mutually at right angles to each other; the thumb shows the direction of motion, the fore finger shows the direction of the field while the middle finger shows the direction of the current.

Hence, if the alpha particle is projected eastwards(at right angles) to the uniform magnetic field, it will be deflected southwards in the magnetic field.

ANSWER:

0.4081%

Explanation:

Difference=24.6-24.5=0.1

Relative error = 0.1/24.5*100=0.4081%

Relative error is equal to the = difference between both the values/The true value *100

laws of reflection

I = r

angle of incident = angle of reflection

35 = 35

Explanation:

momentum = mass x velocity

initial momentum = 100 x 15 = 1500kgm/s

after momentum = 100 x 20 = 2000kgm/s

a =(v-u)/t

a = (20-15)/10

a = 5/10

a = 0.5m/s²

f = ma

f = 100 x 0.5

f = 50N

Answer:

3.3×10⁻⁹ kg/s

Explanation:

There are two forces on the particle: weight force pulling down and drag force pushing up.  At terminal velocity, the speed is constant, so the acceleration is zero.

∑F = ma

bv − mg = 0

b = mg / v

b = (10⁻¹³ kg) (9.8 m/s²) / (3×10⁻⁴ m/s)

b = 3.3×10⁻⁹ kg/s

Answer:

Explanation:

Films are widely popular and their audio visual nature provides them a pervasive power for social influence. Therefore, they have the potential to play an important role as a medium of entertainment, information and education and as a catalyst for social change. Films are popular because they entertain.

Movies are about sitting in a theatre, watching something- watching a story unfold with people you don't know- watching that happen and emoting an emotion knowing that for those two hours or so, when one walks into that theatre, he/she don't have to worry about what is going on outside.

Answer:

The minimum riding speed relative to the whistle (stationary) to be able to hear the sound at 21.0 kHz frequency is 15.7  m/s

Explanation:

The Doppler shift equation is given as follows;

[tex]f' = \dfrac{v - v_o}{v + v_s} \times f[/tex]

Where:

f' = Required observed frequency = 20.0 kHz

f = Real frequency = 21.0 kHz

v = Sound wave velocity = 330 m/s

[tex]v_o[/tex] = Observer velocity = X m/s

[tex]v_s[/tex] = Source velocity = 0 m/s (Assuming the source is stationary)

Which gives;

[tex]20 = \dfrac{330- v_o}{330+0} \times 21[/tex]

330 - [tex]v_o[/tex] = (20/21)*330

[tex]v_o[/tex] = 330 - (20/21)*330 = 15.7 m/s

The minimum riding speed relative to the whistle (stationary) to be able to hear the sound at 21.0 kHz frequency = 15.7  m/s.

Answer:

7.5 Ω

Explanation:

Voltage = Current x Resistance

(V = IR)

240 = 32 R

R = 240 / 32

= 7.5 Ω